JPH0230275B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to the field of sewing machines, and more particularly to an improved feed device for sewing machines.

In feeders for sewing machines, the parts of the feeder are robust and have a low inertia so as to limit the force required to actuate the parts and the actuating force required to adjust the parts. It is desirable to have one. This is a cam that can form a pattern with a variable feed section to reduce wear on the cam containing the feed information or to reduce the load on the linear motor that carries out the feed information sent from an electrostatic storage device. This applies in particular to sewing machines having a mechanism known as a controlled feed section.

Additionally, an ideal feeder would be adapted for use with a tubular bed where the feeder is sufficiently compact to fit inside a housing that may extend into the interior of the sleeve, for example. One feature of home sewing machines that can convert a sewing machine with a flat bed into a structure with a tubular bed is that such sewing machines are adapted for sewing work at home, especially for the production of garments, so that people who do sewing work at home can do so. is becoming increasingly popular.

What is needed is a sewing machine that has the required strength, maintains low inertia, and is compact enough to be used with tubular beds. Furthermore, such an arrangement should be of economical and flexible construction form.

The above requirements are met in a feed device which uses parts made of sheet metal as far as possible in order to obtain lightweight, robust elements exhibiting the desired low inertia. The forward feed is obtained by a cam of constant width mounted on the upper shaft of the sewing machine, and transferred to the horizontal feed shaft in the bed of the sewing machine by a forked rod made of thin plate with a longitudinal channel structure. This increases the strength of the sewing machine in the direction perpendicular to the channel. The feed dog is formed with two upright arms. These arms are connected by shouldered screws to a horizontally arranged U-shaped sheet feed dog. The feed dog is mounted on a ledge extending horizontally from the base of the U-shaped thin plate feed dog carrier. One end of the thin plate lift lever is formed with a groove for accommodating a pin extending from the base of the U-shaped feed dog carrier below the feed dog toward the horizontal feed shaft. The lift lever is pivoted about the center of the machine frame on an eccentric stud having a shoulder and a stud extending from the opposite end of the groove at right angles to the groove. This stud carries a roller that contacts a lift cam carried on an upright shaft above the sprocket for the loop taker device of the sewing machine. The extension of the feed dog above the sewing machine throat plate is controlled by adjusting the position of an eccentric stud having a shoulder on which the lift lever is pivoted. All sheet metal parts are constructed to give maximum moment of inertia in the direction of the force they transmit, and thus maximum strength. If necessary, e.g.
In the case of a two-pronged rod made of sheet metal, the strength of the sheet metal part can be increased by shaping it in such a way as to increase this composite. The present invention provides a compact feeder using a low inertia section with sections made of sheet metal and with separate advance and lift cams to simplify redesign and replacement and optimize feed characteristics. It is something. Other objects and advantages of the invention will be apparent from the following description of one embodiment of the invention, and the novel features are pointed out with particularity in the claims.

The invention is illustrated in the accompanying drawings.

Referring specifically to FIG. 1, a sewing machine 10 incorporating a feeder is shown in dotted lines. A portion of the horizontal upper shaft 12 is shown within the bracket arm 14 of the sewing machine 10 and can be driven in any of a number of ways well known in the sewing machine art. A combined bevel gear and forward cam 16 is supported on the upper shaft 12 . Combined bevel gear and forward cam 1
The forward cam portion 18 of 6 is a cam having a constant width;
That is, the cam can be constructed in various types, such as a cam having a constant thickness that smoothly shifts its position mainly from one side of the axis of the horizontal upper shaft 12 to the other side. The forward cam section 18 is bridged by a forked section 21 of a forked rod 20 made of sheet metal. The sheet metal bifurcated rod 20 is integrally formed from sheet metal and can be expanded to form a channel, designated 22, to increase its lateral strength. The forked portion 21 of the forked rod 20 is formed by an outwardly bent portion of sheet metal to provide an enlarged bearing surface for the advancing cam portion 18. Pin 23 connects from forked rod 20 to slider block 24
extends into the Slider block 24 is captured in a slider of a feed adjustment device 26 which is pivotally carried on sewing machine 10. Also shown is a feed adjustment lever 28. A feed adjuster lever 28 is pivotally connected to the feed adjuster 26 and adjusts the feed to change the advance by changing the slope of the feed adjuster 26, as is well known in the sewing machine art. device control assembly 30.

The lower end of the two-pronged thin plate rod 20 has an eccentric screw 32.
and is adjustably connected by a nut 33 to an arm 35 of a horizontal feed shaft 34 supported on a bullet-shaped center 36. Bullet center 36 is held in place in the frame of sewing machine 10 by set screw 37. The horizontal feed shaft 34 is a slider block 24 set in the feed adjustment device 26.
Since the forked rod 20 is connected to the forked rod 20, it swings in response to the vertical movement transmitted by the forked rod 20. 1 at the opposite end of the horizontal feed shaft 34.
A pair of upright swinging arms 38 are formed.
The swing arm 38 is connected to the opposite end of the U-shaped feed dog carrier 42 by a screw 39. The base of the U-shaped feed dog carrier 42 is formed with an upwardly extending portion 43 (see FIG. 3).
The upward extension 43 terminates in a horizontally extending ledge 44. A feed dog 46 is attached to the horizontally extending shelf portion 44 by screws 47. Studs 45 extend inwardly from the downwardly extending portion 48 from the base of the U-shaped feed dog carrier 42 below the upwardly extending portion 43 and clamp onto the downwardly extending portion 48 by any of a variety of means, including swaging. be able to.

In Figures 1 and 2, a thin plate lift lever 5 is shown.
2 is shown. The lift lever 52 is the sewing machine 10
It is pivoted in a substantially central position on an eccentric stud 55 having a shoulder carried by the bed 15 of the head. One end of the thin plate lift lever 52 has a U.
A slot is formed, indicated at 53 (FIG. 3), for receiving a stud 45 attached to the downward extension 48 from the base of the shaped feed dog carrier 42. The walls of the slot 53 are rounded (see FIG. 3) to ensure smooth operation and free movement without restriction. The other end of the lift lever 52 is provided with a pin 54. A pin 54 is secured to the lift lever 52 and extends transversely thereto. Pin 54 supports roller 58. roller 58
is a vertical upper shaft 64 supported by a column 68 of the sewing machine 10 that connects the bracket arm 14 to the bed 15.
It engages with a lift cam 60 fixed to. The upper end of the vertical upper shaft 64 has a bevel gear and a forward cam 1.
It carries a bevel gear 65 in driving engagement with the bevel gear 17 of 6. A coil spring 62 is seated in the hole of the boss 63 of the bed 15 and extends between the bed 15 and the lift lever 52 made of a thin plate so that the roller 58 at the end of the lift lever 52 always engages with the lift cam 60. is being pressed. lift lever 52
can be formed into a channel as shown at 70 to further increase its strength, and when lifting the feed dog against the resistance of any of the various presser foot devices well known to the sewing machine art. used along the edges to give composition and strength. Vertical upper shaft 6 below the lift cam 60
4 supports a pulley 72, shown partially cut away in FIG. The pulley 72 can be provided with teeth of various shapes to accommodate a timing belt 74 which provides a connection with a second pulley 76 carried on the end of a shaft 78 fixed to a loop taker device 80. . Separate feed lift cam 6
0 allows the feed path to be optimized for best performance by replacing the lift cam 60 by the simple method of removing the pulley 72 and replacing the lift cam 60 mounted on the vertical upper shaft 64. Fine adjustment of the height of the feed dog 46 above the throat plate, which is normally used in sewing machines and is not disclosed herein for simplicity of illustration, is achieved by eccentrically adjusting the eccentric stud 55 with a shoulder. This can be done by causing the feed dog 46 to more or less protrude above the throat plate by rotating the eccentric stud 55.

In this manner, the forked rod 20 converts motion from the cam portion 18 of the bevel gear and advance cam 16 into rocking motion of the horizontal feed shaft 34. Two-pronged rod 20
It is constructed from lightweight and sturdy thin plate members.
The horizontal feed shaft 34 swings using a U made of thin plate that is lightweight, has low inertia, and has high strength.
It is transmitted to the feed dog 46 by the shaped feed dog carrier 42 . The U-shaped feed dog carrier 42 is brought into contact with the workpiece for transporting it by means of a lift lever 52 made of sheet metal that pivots in the bed of the sewing machine in a direction perpendicular to its thickness to achieve maximum strength and composition. It is raised to a predetermined position together with the feed dog 46 that is in use. A first end of the lift lever 52 is formed with a slot designated 53 in conjunction with the U-shaped feed dog carrier 42, and the other end of the lift lever 52 is mounted on an upper vertical shaft 64. It has a pin 54 extending from the lift lever to support a roller 58 that engages a separate and replaceable lift cam 60. A feed device constructed in this way has a very low inertia, is highly compact and has a very economical and flexible form of construction.

It will be understood that various changes in details, materials and construction and operating conditions of the parts described and illustrated herein to illustrate the nature of the invention may be made by those skilled in the art while remaining within the principle and scope of the invention. Good morning.

[Brief explanation of drawings]

Figure 1 is a perspective view of the sewing machine with the feeder of the sewing machine shown in dotted lines to clearly show the feeder;
3 is a bottom view of the sewing machine shown in the figures, and FIG. 3 is a side view of the sewing machine shown in FIG. 2 taken substantially along line 3--3. 10...Sewing machine, 12...Horizontal upper axis, 15...
Bed, 16...Bevel gear and forward cam, 18
...Forward cam part, 20...Two-pronged rod, 21...
... forked portion, 23 ... pin, 24 ... slider block, 26 ... feed adjustment device, 28 ... feed adjustment device lever, 30 ... feed adjustment device control assembly, 34 ... horizontal feed shaft, 35 ... ...Arm, 38
... Swinging arm, 42 ... Feed dog carrier, 44
... Shelf-shaped portion, 45 ... Stud, 46 ... Feed dog, 47 ... Screw, 52 ... Lift lever, 53
...Slot, 54...Pin, 55...Stud, 58...Roller, 60...Lift cam, 64
...Vertical upper shaft, 65...Bevel gear, 70...Channel.

Claims (1)

[Scope of Claims] 1 frame, a horizontal upper shaft pivotally supported in the frame, a vertical upper shaft extending downward from a position adjacent to the horizontal upper shaft, and connecting the horizontal upper shaft to the vertical upper shaft. A feed device for a sewing machine having a rotatably coupled device and a device for selectively driving the horizontal upper shaft, a feed cam fixed to the horizontal upper shaft, and a feed cam fixed to the horizontal upper shaft; a horizontal fork rod having a parallel bent portion hugging the feed cam and having a parallel bent portion in driving engagement with the feed cam, and an arm supported in the frame and connected to the other end of the fork rod; a feed shaft; a feed adjustment device carried by the frame and connected to the forked rod for converting the movement induced by the feed cam into a rocking motion of the horizontal feed shaft; A pair of straight swinging arms is formed at the other end of the straight swinging arms, and each end is connected to one of the straight swinging arms.
a horizontally disposed U-shaped sheet metal feed dog carrier connected to each other, said feed dog carrier having a horizontal ledge extending from the base of the U-shaped member between its ends; a shaped portion supports a feed dog thereon, further comprising a device for attaching the feed dog to the ledge and a stud fixed to the base of the feed dog carrier below the ledge; a sheet metal lift lever pivotally mounted on a horizontal axis in the frame substantially parallel to the horizontal feed axis, the lift lever having a slot for engaging the stud extending from the feed dog carrier; the lift lever has a second end that supports a cam follower adjacent to the vertical upper shaft;
A feed device for a sewing machine, comprising a lift cam removably secured to the upper vertical shaft and engaging the cam follower on the lift lever. 2. In the feed device for a sewing machine according to claim 1, a channel extending in the longitudinal direction is selectively formed in the thin plate forked rod, the feed dog carrier, and the lift lever in order to increase their rigidity. A feeding device for a sewing machine, characterized in that a thinner plate can be used in order to reduce its inertia.